Underwater fuse



Oct. 4, 1966 D. K. TOWER ETAL UNDERWATER FUSE 5 Sheets-Sheet 1 Filed March 4, 1965 Oct. 4, 1966 T W ETAL 3,276,368

UNDERWATER FUSE Filed March 4, 1965 5 Sheets-Sheet 2 ATTORNEY Oct. 4, 1966 D. K. TOWER ETAL 3,276,368

UNDERWATER FUSE Filed March 4, 1965 3 Sheets-Sheet 5 I N VENTORJ BY Z Dell K. Tower, James R. Quinn,

United States Patent 3,276,368 UNDERWATER FUSE George J. Hack, and Robert M. Johnson, Poughkeepsie, N.Y., assignors to Weston Instruments, Inc., Newark, N.J., a corporation of Delaware Filed Mar. 4, 1965, Ser. No. 437,144

Claims. (Cl. 102-16) This invention relates to an underwater fuse and, more particularly, to an underwater fuse which is armed by hydrostatic pressure and fired by the occurrence of an event.

In the operation of embedment anchors it is desirable to use a fuse which will not arm the anchor until the anchor is underwater and a safe distance from the vessel from which it is lowered. Additionally, the fuse must provide a reliable method of firing the anchor when the anchor is at a predetermined stand off distance from the bottom of the body of water into which the anchor is to be embedded. Safety pins provide a reliable means of maintaining a fuse safely unarmed at the surface or on board a vessel. However, such pins must be removed before the anchor or apparatus is lowered from the vessel into the water or be removed by a diver after the anchor is placed in the water. Therefore, additional means must be used to prevent arming of the fuse until the anchor has been lowered into the water a safe distance from the boat or vessel.

It is therefore an object of the present invention to provide a new and improved underwater fuse.

Another object of the present invention is to provide a new and improved fuse which is safety armed by hydrostatic pressure and reliably detonated upon the occurrence of an event.

Still another object of the present invention is to provide a new and improved underwater fuse which is armed by hydrostatic pressure and detonated at a predetermined stand off distance from the bottom of a body of water.

A further object of the present invention is to provide a new and improved underwater fuse for use with an embedment anchor wherein the fuse is armed by hydrostatic pressure and the arming of the fuse releases an interlocking means to place the fuse in condition for detonation upon the arrival of the anchor at a predetermined distance from the bottom of the body of water.

With these and other objects in view, the present invention contemplates an underwater fuse armed by hydrostatic pressure and having an explosive detonator fired upon the occurrence of an event. The fuse includes a housing having a piston movable therein in response to changes in hydrostatic pressure. A detonator is positioned on the piston and moves with the piston in response to changes in hydrostatic pressure to align the detonator with a mechanical or electrical firing means. When an electrical firing means is used, the fuse is activated by remote means from the surface. When a mechanical firing means is used, an interlocking means is released by movement of the piston under hydrostatic pressure to permit the firing means to mechanically strike the detonator in response to contact of a firing rod with the bottom of the body of water.

A complete understanding of this invention may be had by referring to the following detailed description when read in conjunction with the accompanying drawings illustrating embodiments thereof, wherein:

FIG. 1 shows an embedment anchor incorporating a fuse of the present invention, with phantom lines showing the anchor in an operated condition and heavy lines showing an unexpended portion of the anchor assembly being retrieved to the surface;

FIG. 2 is an elevational view of the embedment anchor 3,276,368 Patented Oct. 4, 1966 "ice assembly including the fuse embodied in the present invention;

FIG. 3 is an elevational view of the fuse embodying the principles of the present invention;

FIG. 4 is a cross-sectional view line 44 of FIG. 3;

FIG. 5 is a detailed view of the firing in the fuse shown in FIG. 4;

FIG. 6 shows the fuse of FIG. 4 in a partially operated condition; and

FIG. 7 is a cross-sectional view of an alternative embodiment of the fuse.

Referring first to FIG. 2, an embedement anchor assembly 12 is shown suspended from a suitable line or cable 14, the cable :being connected to the anchor by means of an eyebolt 16 at the upper end of the anchor assembly. The anchor assembly generally comprises an elongated barrel or housing 18 and a plunger 20 extending therefrom having flukes 22 pivotally connected to the lower end of the plunger. An explosive charge (not shown) is arranged in the barrel above the piston, the explosive charge and piston forming an anchor gun. The anchor flukes 22 are held in a collapsed position about the plunger by means of a retainer spring 24. A drag plate 26 is positioned about the upper end of the housing 18. A fuse assembly 28 is mounted on the housing above the drag plate. A pivot plate 30, which is associated with the operation of the fuse, is mounted about the fuse above the drag plate. A firing rod 32, which is connected at its upper end to the pivot plate, extends through the drag plate and downwardly along the side of the anchor assembly to a point beyond the bottom of the anchor. A bottom engaging plate 34 on the lower end of the firing rod provides the rod with a contacting surface for engagement with the bottom of the body of water in which the anchor is to be embedded.

A pendant or cable 36 extends between the anchor barrel and an anchor line 38 depending from a surface vessel. The major portion of cable 36 is positioned with an expendable housing 40 which is attached to the anchor assembly. An embedment anchor of the type referred to above is more fully described in the copending application of Murl H. Anderson, Serial No. 289,170, filed June 17, 1963 and now Patent No. 3,207,115, entitled Explosive-Operated Anchor Assembly.

FIG. 1 illustrates the anchor assembly after it has been operated with the anchor embedded in the ocean floor and the recoverable portion of the assembly being retrieved to the surface by means of cable 14. The phantom lines show the anchor assembly in the firing position.

FIG. 3 shows the fuse assembly 28 in association with the upper end of the anchor housing 18. The firing rod 32 is shown extending through an opening in the drag plate. The firing rod is sized to slide within the opening in the drag plate. A snap ring 42 is received in a groove on the firing rod below the drag plate. A spring 44 is positioned about the firing rod between the snap ring 42 and the lower surface of the drag plate. A second snap ring 45 is received in a groove in the firing rod above the drag plate to limit the downward movement of the rod through the opening in the plate. The pivot plate 30 has a downwardly extending flange 46 about its outer edge which rests on the upper surface of the drag plate. An opening is provided in the center of the pivot plate to receive the fuse assembly therethrough for connection to the upper end of the anchor housing. A pair of smaller openings 48, 50 are provided on opposite sides of the pivot plate near its outer periphery. Opening 48 loosely receives a headed screw 52 for fastening the pivot plate to the upper end of the firing rod 32. The opposite side of the pivot plate is also loosely held in position on the drag plate by means of a screw of the fuse taken along pin mechanism 54 received through the opening 50. The flange 46 formed on the pivot plate provides a pivot point 56 on one side of the plate to permit upward pivotal movement of the plate when the firing rod 32 moves upward to lift the opposite side of the pivot plate. A hole 58 is provided in the firing rod 32 just below the lower surface of the drag plate for receiving a safety pin (not shown) to prevent inadvertent upward movement of the rod.

The fuse assembly includes a housing 60 and an outer sleeve 62 slidably mounted about the fuse housing. A spring retainer ring 64 is positioned in a groove at the upper end of the fuse housing. A spring 66 is positioned about the fuse housing between the retainer ring and an upper flanged end 68 of the sleeve 62. An outwardly extending flange 70 is also formed on the lower end of the sleeve to provide a surface for contact with the pivot plate 30 upon upward movement of the pivot plate. The eyebolt 16 which is connected to the upper end of the fuse housing provides means for connecting the line 14 to the fuse and the anchor assembly. A circular opening 72 and an elongated vertical opening 74 are provided in the side of the sleeve for purposes to be later described. A downwardly projecting threaded portion 76 is formed on the fuse housing to provide means for connecting the fuse to a breech 78. The breech 78 is threadedly received in the upper end of the anchor housing. An initiator or booster 80 is positioned in a vertical passage 82 formed through the breech.

In FIG. 4, the fuse assembly 28 is shown in cross section. A vertical passageway 84 is formed through the fuse housing 60. A transverse cylinder or bore 86 is formed part way through the housing near its lower end and intersects the vertical passageway 84. A piston or slider 87 is slidably received within the cylinder 86. A recess 88 in one end of the slider 87 receives one end of a spring 89 therein which spring is positioned between slider 87 and the blind end 91 of the cylinder. A guide slot 92 is formed on one side of the cylinder. A pin 93 extends upwardly from the base of the housing into the guide slot to prevent the piston from rotating within the cylinder. A vertical bore 94 is formed through the piston, the bore 94 having an enlarged portion 96 for receiving a detonator 97. A transverse hole 98 is formed in the outer end of the piston for receiving a safety pin to prevent inadvertent movement of the slider within the cylinder. The cylinder 86 is enlarged at its open end to receive an annular seal 99 for effecting a fluid-tight seal between the fuse housing and the slider 87. A portion of the enlarged end of the cylinder is threaded to receive an annular plug 101 for maintaining the sealing means 99 in its position between the fuse housing and the slider.

A second transverse bore 102 is formed part way through the housing above and parallel to the cylinder 86. A shaft 104 is rotatably positioned within the bore 102. A ball 106 provides a low-friction bearing surface be tween the blind end 108 of the bore and the shaft to facilitate rotation of the shaft which is pressed inwardly into the bore by hydrostatic pressure when the fuse is submerged. A notch or flat 110 is formed on one side of the rotatable shaft. An enlarged end portion 112 of the shaft extends outwardly of the fuse housing. A lever arm 114 is secured to the end of the rotatable shaft, and a tang 116 is formed on the end of the lever arm. The sleeve 62 which is positioned about the fuse housing is provided with an outwardly extending stop tab 117 which engages the tang 116 formed on the lever arm when the sleeve is held in its downward position by the spring 66. The enlarged end 112 of the shaft has an annular recess 118 therein which receives a pin 120 extending downwardly from the fuse housing into the recess to prevent the shaft 104 from moving longitudinally within the bore 102. An O-ring seal 122 is received within an enlarged portion 124 of the bore 102 between the housing and the shaft for providing a fluid-tight seal between the housing and shaft to thereby prevent fluids from entering the interior of the fuse housing.

The vertical passageway or bore 84 formed through the housing has an enlarged upper portion 125 which is threaded to receive the eyebolt 16. An intermediate bore portion 126 is formed between the upper enlarged portion 125 and the smaller part of the passageway 84. A firing pin 128 is positioned in the intermediate bore portion 126. The firing pin has an enlarged end 130 which is recessed to receive a firing pin spring 132 therein. The other end of the spring 132 is received in a recessed end portion 134 of the eyebolt, the spring being positioned between the eyebolt and the firing pin. An annular seal 136 is positioned in a groove in the upper end of the fuse housing between the housing and eyebolt to prevent fluid from entering the interior of the fuse housing. A shoulder 138 '(see FIG. 5) is formed on the firing pin between its upper enlarged end 130 and a hammer end 140. The enlarged portion of the firing pin is positioned within the intermediate bore 126 so that the shoulder portion 138 on the firing pin rests on the flat 110 formed on the rotatable shaft 104. The hammer portion 140 on the firing pin is sized to be movably received within the vertical passageway 84 in the fuse housmg.

When used with an embedment anchor, the abovedescribed fuse is threadedly secured into the breech 78 of the anchor gun in the upper end of the anchor housing (see FIG. 3). Water-tight integrity is maintained in the gun by means of .an O-ring seal (not shown) which is positioned in a recess 142 on the lower end surface of the fuse housing. The cable or recovery line 14 is [attached to the eyebolt 16 at the upper end of the fuse. The anchor line 38 from the surface is attached to a shackle at one end of the cable or anchor pendant 36, the other end of the pendant being fastened to the anchor plunger 20. When the anchor assembly is ready to launch into the water, safety pins in the detonator slider and firing rod are removed. As the anchor and gun assembly sink to the bottom, the detonator slider 87 is moved into an armed position by means of hydrostatic pressure acting on the outward end of the slider. This openation of the fuse is shown in FIG. 6. The slider spring 89 is designed so that a preselected hydrostatic force corresponding to a fixed depth is required to move the slider to an armed position. Upon movement of the slider to the right, the lefthand end of the slider clears the opening 72 in the fuse sleeve thereby freeing the sleeve for upward movement against the action of sleeve spring 66.

Thereafter, when the fining or contact nod 32 contacts the bottom, the upper end of the firing rod raises above the drag plate to lift one end of the pivot plate 30 (FIG. 3). This upward movement of the pivot plate causes the plate to engage the lower flanged edge 70 of the fuse sleeve 62, the other end of the pivot plate pivoting about the pivot point 56 formed by the left flanged end of the plate. Further upward movement of the pivot plate lifts the sleeve 62 upwardly against the force of spring 66.

This upward movement of the sleeve 62 moves the stop tab 117 on sleeve 62 to a position clear of the inwardly extending tang 116 on the lever :arm. This in turn frees the lever arm to permit rotation of the shaft 104 which is connected to the lever arm. The firing pin spring 132 which urges the firing pin downwardly also acts through the fining pin 128 to rotate the flat surface 110 on shaft 104 toward a vertical position. This positioning of the shaft and flat surface frees the firing pin for downward movement under the force of spring 132. As the firing pin moves downwardly, the hammer end 140 of the pin moves through the vertical passage 84 and into the now aligned vertical bore 94 in the slider 87. Further downward movement of the firing pin causes the hammer to strike the detonator 97 in the slider to produce an eX- plosion which is transmitted into the breech of the anchor gun by means of the passageway 84 which continues through the downwardly projecting portion 76 of the fuse. The initiator 80 located in the breech is then ignited to provide a sulficient explosive force to detonate a large explosive charge in the anchor gun. Detonation of the large explosive charge forces the plunger 20 and anchor from the lower end of the gun to embed the anchor in the bottom of the body of water. Subsequent tension on the anchor line from the surface vessel causes the flukes 22 on the anchor to extend outwardly thereby further securing the anchor in the ocean floor as shown in FIG. 1.

An alternative embodiment of the fuse apparatus is shown in FIG. 7 and features an electrical firing mechanism in association with the hyd-rostatioally armed fuse. The electrical fuse finds particular application Where precision emplacement of the anchor is required. The anchor and gun are mounted on a tripod and. placed into position on the ocean floor by a diver. Firing of the gun is accomplished remotely by directing energy from an elec trical firing box at the surface (not shown) through a connecting cable to an electrical squib 152 in the fuse. The fuse generally consists of a body or housing 154 having a threaded downwardly extending portion 156 which is received within the breech of the anchor gun. An eyebolt 158 having a lower threaded portion 160 is threadedly secured to the upper end of the fuse housing. A vertical bore 162 extends through the fuse housing, the bore having an enlarged upper end for receiving the threaded end of the eyebolt. A recess 164 is formed in the threaded portion 160 of the eyebolt. The electrical squibs 152 are potted in the recess 164 and are aligned with the vertical bore 162 extending through the fuse housing.

A transverse bore 166 is formed through the fuse housing and intersects the vertical bore 162. A detonator slide 168 is positioned within the bore. A transverse bore 169 is formed through the slide 168 and a detonator or initiator 171 is positioned in the bore 169. A spring 170 is positioned between the blind end of the bore 166 in the fuse housing and a recessed end portion 172 of the detonator slide. A slot 174 is formed in the wall of the slide for receiving a pin 176 extending from the housing to prevent the slide from rotating within the bore and from inadvertently falling out of the bore. The outer end of the cylindrical bore is enlarged to receive an annular seal 178 between the fuse housing and the detonator slide. The bore is threaded to receive an annular end plug 180 for maintaining the seal in position. A hole is formed transversely through the end of the detonator slide to receive a safety pin 182 which prevents movement of the slide to an armed position unless the pin is removed. Conductors 184 extend from the base of the eyebolt to provide an electrical connection between the electrical squib and a .shot or firing line extending from the surface vessel.

In operating the electrical fuse just described, the fuse and anchor assembly are fastened to a support tripod. After it is determined that the firing line is shortened at the firing control end, the firing line is attached to the fuse. The gun recovery line is attached to the eyebolt 158 and the anchor line is attached to the shackle of the anchor line pendant fastened to the anchor. The complete assembly is then lowered to the bottom of the body of water. The safety pin 182 is withdrawn from the fuse by a diver or by other means. Hydro-static pressure will move the detonator slide into a firing position so that the electrical squibs 152 upon firing will detonate the initiator 171 in the detonator slide which, in turn, will detonate a second initiator 80 (see FIG. 3) in the breech of the anchor gun. Upon igniting of the elements in the firing train, the anchor is propelled from the anchor housing and into the bottom of the body of Water.

While the fuse apparatus which is the object of the present invention has been described for use with an embedment anchor, it is readily seen that such fuse would have other uses with underwater explosive devices. Ad-

ditionally, while particular embodiments of the present invent-ion have been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A fuse apparatus comprising: a housing defining a recess therein, a cylindrical member rotatably mounted for rotation about its longitudinal axis within said recess, said cylindrical member being releasalbly held in a first rotative position, a passage in said housing communicating with said recess, means for hydrostatically sealing said passage and said recess, pin means slidably mounted in said passage and being normally held in a nonfiring position, explosive means in said housing and arranged for detonation upon movement of said pin means from said nonfiring position to a firing position, means on said cylindrical member for maintaining said pin means in said nonfiring position when said cylindrical member is in said first rotative position, resilient means in said housing for urging said pin means to assume said firing position and for urging said cylindrical member to rotate from said first rotative position to said second rotative position, and means mounted on said housing and being responsive to the occurrence of an event for releasing said cylindrical member for rotation to said second rotative position.

2. A fuse for underwater use comprising: a housing, explosive means mounted on a slide member and movable between first and second positions within said housing in response to pressure changes, means for detonating said explosive, said detonating means being adapted to be impelled against said explosive means in said second position, first latch means releasably holding said detonating means in a first position away from said explosive means, releasably held second latch means movable from a position holding said first latch means to a position releasing said first latch means, and means responsive to movement of said explosive means toward said second position for releasing said second latch means for movement to its said position releasing said first latch means.

3. A fuse for underwater use comprising: a housing, piston means movable between first and second positions within said housing in response to pressure changes, explosive means mounted on said piston, means for detonating said explosive means, means for impelling said detonating means against said explosive means when said piston means is in said second position, releasably held latch means normally maintaining said detonating means in a position spaced from said explosive means, releasably held sleeve means about said housing and movable from a position holding said latch means to a position releasing said latch means, and means responsive to movement of said piston means toward said second position for releasing said sleeve means for movement to said position releasing said latch means.

4. A fuse apparatus for operating an embedment anchor on the bottom of a body of water comprising: a housing, piston means movable between first and second positions within said housing in response to hydrostatic pressure changes, said piston defining an opening therethrough, explosive means positioned in said opening, said housing defining a passage means arranged to be aligned with said opening when said piston means is in said second position, pin means slidably mounted in said passage for detonating said explosive means, resilient means for impelling said pin means against said explosive means when said piston means is in said second position, releasably held latch means normally maintaining said pin means in a position spaced away from said explosive means when said piston means is in said second position, releasa bly held sleeve means about said housing and movable from a position holding said latch means to a position releasing said latch means, means responsive to movement of said piston means toward said second position for releasing said sleeve means for movement to said position releasing said latch means, resilient means mounted on said housing for normally maintaining said sleeve means in said position holding said latch means, and means responsive to the contact of a portion of said apparatus with the bottom of the body of Water for moving said sleeve means to said position releasing said latch means.

5. A fuse apparatus for operating an embedment anchor on the bottom of a body of water comprising: a housing, piston means movable between first and second positions within said housing in response to hydrostatic pressure changes, said piston defining an opening therethrough, explosive means positioned in said opening, said housing defining a passage means arranged to be aligned with said opening when said piston means is in said second position, pin means slidably mounted in said passage for detonating said explosive means,

.means for impelling said pin means against said explosive means when said piston means is in said second position, releasably held latch means normally maintaining said =pin means in a position spaced away from said explosive means when said piston means is in said second position, releasably held sleeve means about said housing and movable from a position holding said latch means to a position releasing said latch means, means responsive to movement of said piston means toward said second position for releasing said sleeve means for movement to said position releasing said latch means, resilient means mounted on said housing for normally maintaining said sleeve means in said position holding said latch means, a pivotally mounted sleeve engaging member positioned adjacent said sleeve means and arranged to move said sleeve means to said position for releasing said latch means when said sleeve engaging member is pivoted, and firing means extending from said fuse apparatus and spaced a predetermined distance from the lower end of said anchor for pivoting said sleeve engaging member upon contact of said firing means with the bottom of the body of water.

References Cited by the Examiner UNITED STATES PATENTS 3,015,270 2/1962 Domingos et al. 102-7 3,035,285 5/1962 Squires 114206 X 3,102,475 9/1963 BeckWith 102-16 BENJAMIN A. BORCHELT, Primary Examiner.

V. R. PENDEGRASS, Assistant Examiner. 

1. A FUSE APPARATUS COMPRISING: A HOUSING DEFINING A RECESS THEREIN, A CYLINDRICAL MEMBER ROTATABLY MOUNTED FOR ROTATION ABOUT ITS LONGITUDINAL AXIS WITHIN SAID RECESS, SAID CYLINDRICAL MEMBER BEING RELEASABLY HELD IN A FIRST ROTATIVE POSITION, A PASSAGE IN SAID HOUSING COMMUNICATING WITH SAID RECESS, MEANS FOR HYDROSTATICALLY SEALING SAID PASSAGE AND SAID RECESS, PIN MEANS SLIDABLY MOUNTED IN SAID PASSAGE AND BEING NORMALLY HELD IN A NONFIRING POSITION, EXPLOSIVE MEANS IN SAID HOUSING AND ARRANGED FOR DETONATION UPON MOVEMENT OF SAID PIN MEANS FROM SAID NONFIRING POSITION TO A FIRING POSITION, MEANS ON SAID CYLINDRICAL MEMBER FOR MAINTAINING SAID PIN MEANS IN SAID NONFIRING POSITION WHEN SAID CYLINDRICAL MEMBER IS IN SAID FIRST ROTATIVE POSITION, RESILIENT MEANS IN SAID HOUSING FOR URGING SAID PIN MEANS TO ASSUME SAID FIRING POSITION AND FOR URGING SAID CYLINDRICAL MEMBER TO ROTATE FROM SAID FIRST ROTATIVE POSITION TO SAID SECOND ROTATIVE POSITION, AND MEANS MOUNTED ON SAID HOUSING AND BEING RESPONSIVE TO THE OCCURRENCE OF AN EVENT FOR RELEASING SAID CYLINDRICAL MEMBER FOR ROTATION TO SAID SECOND ROTATIVE POSITION. 